Satellite Begins Its Search For Mysterious Black Hole

June 21, 1985|By James Fisher of The Sentinel Staff

CAPE CANAVERAL — With the precision touch of a jeweler, shuttle astronauts used Discovery's robot arm Thursday to launch a science satellite that will scan the center of the Milky Way for evidence of an invisible, star-gobbling black hole.

Spartan, a 2,200-pound automated observatory, will measure X-rays emanating from a part of the galaxy 30,000 light-years away. One light-year is about 5.88 trillion miles.

Spartan also will study a group of more than 1,000 galaxies 300 million light-years away in the constellation Perseus, gathering data that may reveal secrets about the formation of the universe.

The satellite will be retrieved Saturday for return to Earth.

Meanwhile, NASA moved up a second attempt to test Star Wars laser technology from Saturday to today. The first try failed Wednesday when a misprogrammed autopilot pointed Discovery 180 degrees in the wrong direction, out of view of a laser beam from Earth.

The release of Spartan was a delicate engineering ballet. Just before noon, the robot arm slowly placed the 10-by-4-foot satellite about 30 feet out of the cargo bay and aimed it before letting go.

Mission specialist Shannon Lucid released the arm's grasp and began inching the 50-foot tool away from the satellite without so much as a tap while the shuttle orbited 220 miles above the Pacific Ocean north of Hawaii at 17,400 mph.

The satellite was ''steady as a rock,'' commander Daniel Brandenstein reported.

Spartan looked like a white refrigerator as it floated above the blue planet below. Minutes later, argon thrusters fired to slowly turn the spacecraft 45 degrees and then back again, providing a visible signal that its self-contained systems were working.

''Houston, as you can see, it worked just like advertised,'' said mission specialist John Fabian.

Spartan will move as far as 100 miles from the shuttle before the two spacecraft begin moving closer for Saturday's rendezvous.

The $3.5 million satellite, which will be refitted with different instruments for future flights, was named Spartan because of its simplicity. It is programmed to guide itself and record its own data.

Spartan's sleuthing expedition may add to the increasing collection of evidence that an invisible black hole may exist at the Milky Way's core, voraciously sucking in stars, dust and gases.

Research has shown that parts of stars and other matter heat and radiate X-rays as they swirl around a black hole before being pulled in, and that is what Spartan will look for.

Scientists ''will be lucky'' to get direct evidence of a black hole from Spartan, but it could add important pieces to the puzzle, said Ray Cruddace, a scientist for the Naval Research Laboratory in Washington.

''We really don't know what we're going to find. We're just going to go and look.''

When it studies the Perseus group of galaxies, Spartan will pay close attention to gas that heats to 100 million degrees and emits X-rays.

Scientists want to know whether all the gas comes from the stars in the galaxies or whether part of it is residue from the primordial gas from which the galaxies formed, Cruddace said.

Discovery's astronauts will attempt the Star Wars tracking test at 7:30 a.m. today as the shuttle orbits above the Hawaiian island of Maui from which the 4-watt blue laser will originate.

The laser, which should illuminate the front half of the shuttle, will bounce off an 8-inch reflector in the shuttle's lower side window before reflecting back to Maui. The test will study the effects of Earth's atmosphere on the distribution of laser light.

If weather or other problems cause the test to fail again, the crew can try once more Saturday.

Wednesday's test failed because technicians gave the crew the wrong coordinates to enter into the shuttle's autopilot computer.